FLUX Mentor Class-A dual-mono headphone amplifier.

[Slackaveli]

I wish I could hear a stack vs a single unit. I dont even know what Im missing

 

[quawn0418]

I wish I could hear a stack vs a single unit. I dont even know what Im missing

that’s a whole lot of amp, i can only imagine

 

[arijitroy2]

I wish I could hear a stack vs a single unit. I dont even know what Im missing

I'll be honest here, I haven't heard much difference yet! But I haven't also done an A/B testing, too lazy to disconnect and connect wires.

I just bought it to be future proof!

 

[Slackaveli]

Fair, and you have the current-hungry Tungz coming. You'd be totally good to go with a Susvara or Abyss ab-1266 or any future power-hungry HPs as well.

I've got a Mentor but right now only HE1000 so a second Mentor probably won't do much. I've heard people say it's a bit more sound-stage and maybe more meat-on-the-bones with the stack.

 

[LETRA]

I think it really depends on your sound signature preference and your current collection of gear.

For me, I was looking for a more romantic sound without fully committing to expensive OTL amps. I love the tube sound but don't like the hidden costs and hassles of tube rolling. I also already have a neutral and precise amp that I enjoy, so wanted to compliment it with a thicker-sounding solid state. I would personally consider the M-Field (and especially the mono stack) end-game for that purpose.

For an end-game neutral amp, I'm considering a CFA3.

Hi I see in your signature that your chain includes the Topping DX9 and a Flux Mentor dual stack. May I ask if you listen to them together? I have purchased a Mentor pending receipt in UE and have been reading the thread and there is quite a consensus that the Mentor pairs well with a R2R DAC like the Gustard R26. However my Topping DX9 mounts a four channel AK4499EQ DAC chip, which has equivalent performance to the two AK4499EX in the R26. On the other hand if the Mentor just needs “a little warmth” I think the DX9 is different from other Topping models and its DAC has that warmth point. The perfect clarity and transparency of the DX9 would help, as I like the analytical sound. And I really am very happy with the DX9, it is one of the best audio purchases I have made regardless of price.

 

[jsabini1]

Just to follow up, I have asked people and looked all reviews I could find and there is not a single unit with certification. The address of the company is in a random residential building. The product might be solid, but the rest seems shady and risky.

Will be great if anybody has certification on their unit and can share pictures with impressions in this regard plus experience with warranty and repairs.

Cheers.

Shady, no. Risky, probably. And it will continue to be until the war is "over", whatever that looks like...?

 

[Slackaveli]

Hi I see in your signature that your chain includes the Topping DX9 and a Flux Mentor dual stack. May I ask if you listen to them together? I have purchased a Mentor pending receipt in UE and have been reading the thread and there is quite a consensus that the Mentor pairs well with a R2R DAC like the Gustard R26. However my Topping DX9 mounts a four channel AK4499EQ DAC chip, which has equivalent performance to the two AK4499EX in the R26. On the other hand if the Mentor just needs “a little warmth” I think the DX9 is different from other Topping models and its DAC has that warmth point. The perfect clarity and transparency of the DX9 would help, as I like the analytical sound. And I really am very happy with the DX9, it is one of the best audio purchases I have made regardless of price.

I think Mentor would pair well with almost any DAC.

 

[zeek99]

wish i could hear / demo the m-field along with the mentor on how it suits hifiman open-back headphones. i was considering the mjolnir 3 by schiit audio but i'd like something with a remote control and a smaller form-factor. i have the he1000se right now and whatever amp i get would also have to fit the susvara i'll get by next year.

 

[Slackaveli]

Honestly dont think you can go wrong with either.

 

[naimster]

I had the Susvara OG paired up with the Mentors in both single and dual stack configuration. The difference is not trivial with the biggest impact coming from the bass and transparency. In single stack, the bass sounded a little dry and small in relative to the dual stack. In dual stack, the bass got more visceral and more impactful and vibrate quite a bit which made the Susvara sounded more speaker like. Besides that, soundstage got bigger and I am hearing more micro details than before. All in all a very worthwhile upgrade.

 

[Inolvidable]

That above is the signal diagram right?

But By definition:

The single and dual Mono are all balanced. It Not having an SE connection doesn’t make it unbalanced.

See the inside and how they are wired? 2 separate power supplies and pathway. How is that unbalanced?

Ichos​

There are two channels. Left and right. No L+ L- R+ R-.

You see what you started lol.

Seriously, guys, dual-mono is balanced. It's like Eric said- two diverging meanings of the word balanced. SE doesnt been "unbalanced" like the language might suggest. It's much adieu about nothing.

Look at the Flux- it's called "Mono Balanced" on the output. The left and right channels will still be in stereo, and the POWER is there. The reason to run fully balanced is MORE POWER , not 'better sound quality".

Hope this helps. Worry not about the Mentor's quality. The only worry I have at all is I hope they get to exist for years and years and not end up victimized by the aggressor nation...

Based on what I just learned, this is not true. You can have dual mono balanced OR unbalanced.. and also main purpose of balanced is not so much power but lower noise.

but anyway, does not really matter at all in the end.. It was nice to learn again something new .

I'm on the verge of choosing the Mentor, but I had some concerns about the integrity of the balanced signal in a single (dual mono) Mentor setup. To clarify, I reached out to Fluxlab and asked:

"Does a single Mentor Amp have the capability to reject common-noise signals, either at the XLR inputs or outputs?"

Their response:

"The Mentor amplifier has a separate differential line receiver circuit installed at the XLR inputs, specifically designed to handle a true balanced signal. Additionally, when using long interconnect cables, we recommend utilizing the XLR inputs of the amplifier to minimize noise induced along the cable."

Based on my research, it seems that the main advantages of truly balanced amplifiers are higher power output and common-noise signal cancellation.

As far as I understand, the XLR output signal from amplifier to headphones is always balanced, meaning the same information is transmitted through both cables of each channel.

In essence, the Mentor appears to provide high power, effective noise rejection at the input stage, true internal channel isolation, and a balanced signal at the output—covering all the essential bases.

Am I missing something in my conclusions?

 

[Slackaveli]

nope. it's the real deal.

 

[UbdU]

My second Mentor arrived, I'm now using them in dual mono. It's awesome, BUT there is a slight but noticeable volume imbalance when both are on low gain. Medium gain seems balanced, and I haven't tried high gain yet.

*edit: high gain is fine, too

The sound stage gets bigger and there's more detail. Blah blah blah, it's stuff everyone has heard before.

Can't wait until my Tungstens get here in 7 months to use with them.

 

[Ichos]

I'm on the verge of choosing the Mentor, but I had some concerns about the integrity of the balanced signal in a single (dual mono) Mentor setup. To clarify, I reached out to Fluxlab and asked:

"Does a single Mentor Amp have the capability to reject common-noise signals, either at the XLR inputs or outputs?"

Their response:

"The Mentor amplifier has a separate differential line receiver circuit installed at the XLR inputs, specifically designed to handle a true balanced signal. Additionally, when using long interconnect cables, we recommend utilizing the XLR inputs of the amplifier to minimize noise induced along the cable."

Based on my research, it seems that the main advantages of truly balanced amplifiers are higher power output and common-noise signal cancellation.

As far as I understand, the XLR output signal from amplifier to headphones is always balanced, meaning the same information is transmitted through both cables of each channel.

In essence, the Mentor appears to provide high power, effective noise rejection at the input stage, true internal channel isolation, and a balanced signal at the output—covering all the essential bases.

Am I missing something in my conclusions?

Carefully observe the pot. This is not a balanced Alps pot. The Mentor is not a balanced amplifier. It is a dual mono amplifier, that is different from balanced. However I wouldn't care much because as Flux replied, it has a separate differential line receiver circuit installed at the XLR inputs, specifically designed to handle a true balanced signal and offer you the noise rejection you want. It is also very powerful and sounds great too.

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Edit:

I am wrong about the pot.


Flux Labs have chimed in and I am quoting what they said about the amplifier.

"No analog signal goes through the potentiometer and even in a balanced amplifier a single potentiometer is enough. The Alps pot in the Mentor is only a control element connected to a digital control system. The controller itself, through which the signal goes, is located directly next to the input jacks.

But yes, the amplifier is not balanced. That's right. It's only balanced if you use a stack."

 

[Daniel59]

It's awesome, BUT there is a slight but noticeable volume imbalance when both are on low gain. Medium gain seems balanced, and I haven't tried high gain yet.

Interesting….I’ll have to test that out with my new Mentor stack. I just received my Mentor stack last Friday. It only took 12 days from my purchase date to receive the amps! I haven’t even stacked my Mentors yet…no rush….I’ve been taking my time. I had a 5 hr listening session on each unit so far (used one amp on Friday, the other on Saturday ). Even during just 5 hrs, I could tell the amps changed sonically over that time… The first couple of hrs, there was a bit of increased treble energy and bass was a bit boomy, but that all dissipated after the 5 hr mark… I noticed the changes on both amps.

I haven’t listened to a SS amp for a number of months…I’ve been on a portable electronics palette (amps/dacs) for this duration, but did get a couple home DAC’s (R2R and a 4 chip delta Sigma dac)……I’ve been playing my hp’s/iems on portable/transportable tube amps over the past months, so this jump to a powerful SS amplification is quite eye opening. I’m loving the sonic differences already!! I think the amps will continue to improve sonically over the coming 1-2 months, as I approach the 100 hr warm up recommendation by the Flux Lab team. I think my portable gear will be sitting on the sidelines for a while as I grow with this new foundation for my hp listening and audio enjoyment!

I hope to contribute on this thread over the coming months to share my experiences with my Mentor Stack.